Storage area networks (SANs) are typically implemented to interconnect data storage devices and data servers or hosts, using network switches to provide interconnectivity across the SAN. SANs may be complex systems with many interconnected computers, switches, and storage devices. The switches are typically configured into a switch fabric, and the hosts and storage devices connected to the switch fabric through ports of the network switches that comprise the switch fabric. Most commonly, Fibre Channel (FC) protocols are used for data communication across the switch fabric, as well as for the setup and teardown of connections to and across the fabric, although these protocols may be implemented on top of Ethernet or Internet Protocol (IP) networks.
Typically, hosts and storage devices (generically, devices) connect to switches through a link between the device and the switch, with a node port (N_port) of the device connected to one end of the link and a fabric port (F_port) of a switch connected to the other end of the link. The N_port describes the capability of the port as an associated device to participate in the fabric topology. Similarly, the F_port describes the capability of the port as an associated switch.
Over time, SANs have become more complex, with fabrics involving multiple switches that use inter-switch links (ISLs) connected to switch ports (E_ports) on the switches. In some SANs, a core group of switches may provide backbone switching for fabric interconnectivity, with few or no devices directly connected to the core switches, while a number of edge switches provide connection points for the devices or devices of the SAN. Additional layers of switches may also exist between the edge switches and the core switches.
The increasing complexity of enterprise data centers has complicated switch maintenance operations, which require coordination between several administrators in order to complete. The simple act of blocking a port of a network switch to perform a service action can require multiple teams of users to update their operations in order to avoid using the target port. Often the procedures involved with this kind of effort are manual and prone to error.
Some environments are especially sensitive to administrative errors that activate the automated recovery systems. Such systems include call home, device recovery, logical path recovery, and application recovery systems. Thus, errors in coordination of switch maintenance operations that trigger these automated recovery systems create delays and escalations in production environments that enterprise data center managers would like to avoid.